Checking mechanisms stops and stays are known in the art. For example the checking mechanisms are mechanical and include a roller contained in a housing fixed to a vehicle door, the rollers having a rod passing between them and the rod normally has a number of discrete raised portions or recesses. As such a checking mechanism having discrete checking positions at each portion where the recesses are located is provided. A considerable amount of force must be applied by a passenger or operator of the vehicle to move it from the checked position to the moveable position.
It would therefor be advantageous if a simple structure were provided which allows for infinite checking of the door when the in the stopped position and ease of movement of the door when it is in the moveable positions. However, mechanical checks will generally on there own not meet this requirement.
U.S. Pat. No. 4,689,849 to Porsche describes a control mechanism for a door including a piston and a blocking valve. The blocking valve is disposed in a controlled circuit so that it may block the flow to the two working chambers of the cylinder and thus arresting the door in any arbitrary position. However, when the door handle is operated it controls the blocking valve which when released allows the flow of the fluid to the working chambers. In using such a structure it therefor is necessary for an operator opening the door to pull on the inside door handle and hold the inside door handle open while the door is being moved. This is not practical and is quite clumsy in operation. Unless, either in the inside or the outside handle is operated the door will remain in a fixed position unless an over pressure situation occurs. However, there is no discussion as to what characteristic occurs with such an over pressure situation.
It therefor would be beneficial if a door for a vehicle to be checked in position automatically when the door substantially stops its movement and which would be easy to move when the door commences its movement without the need of and operator to operate the door handles. Typically in a vehicle, an operator unlatches the lock and pushes the door open via a molded grip on the inside of the door. When exiting the door is closed merely by shutting the door depending on the model of the vehicle. It would therefor be more practical to allow for such automatic checking.
Other examples of door checks are found in the art such as U.S. Pat. No. 2,036,474, U.S. Pat. No. 3,212,122 among others.
Controlled release door holders are also known in the art, which control the motion of the door and prohibit quick opening or closing of the door. Structure such as U.S. Pat. No. 4,267,619 include accelerated closing of a door during a fire, for example. Canadian Patent 981,707 and 1,010,914 are the equivalents of the 619 reference.
Actuators such as those manufactured by Turn Act as taught in U.S. Pat. No. 4,774,875 among others are known in the art. Also known in the art are U.S. Pat. No. 4,653,141 and U.S. Pat. No. 4,756,051 embodied in a hinge. These structures include damping and shock absorbing features, but do not include checking features.
U.S. Pat. No. 4,889,151 describes a snap-action pressure relief valve which operates by taking advantage of an area 83 as seen in FIG. 1 which provides a higher force to open the relief valve, and a reduced force once the relief valve is opened subjected to the same pressure. However, such a structure is not taught within a check or stay mechanism.
Nowhere within the prior art is there found a check or stay mechanism which provides that when the member being checked is substantially stationary that it is checked automatically by the attributes of the structure and when the member being checked is free to move, it is uninhibited during such a motion until it returns to a checked stationary state.
It is therefor a primary object of this invention to provide a check, stop, or stay for a moveable member which is inhibited from moving when in the substantially stationary position and which is uninhibited automatically when the member is moved and remains in a dynamic state.
It is a further object of this invention, to provide such a mechanism in a vehicle door.
It is yet still another object of this invention, to provide such a mechanism for a rotatable caster, roller or wheel, for example material handling carts.
It is yet still another object of this invention, to provide a check, stay or stop for a moveable member in a simple economical and convenient structure.
Further and other objects of this invention will become apparent to a man skilled in the art when considering the following the summary of the invention and the more detailed description of the preferred embodiments illustrated herein.